Comment 6 for bug 1072694

On 10/30/2012 11:53 AM, corrado maurini wrote:
> Johan,
>
> Thanks a lot for taking care of this.

Well, we see how far it goes :)

> If redirecting ostream through python is too difficult, for the specific
> case a possible alternative can be to have a function similar to
> list_timings(), but giving a dolfin Table as output.

Sure that would be pretty trivial to implement, and we have them same
analogy for list_linear_algebra_backends and linear_algebra_backends,
where the later return a list of strings instead of printing them to the
screen.

So adding a free function called timings would fit fine here.

> Then the Table is a python object and one can use the associated methods
> to access data or print it out (event in latex format!).

Good point!

> I have not done this directly because I do not if this may conflict with
> your general design principles for the logger.

Should work just fine.

Johan

> Corrado
>
> Le 30 oct. 2012 à 11:02, Marco Morandini a écrit :
>
>> On 10/30/2012 08:00 AM, Johan Hake wrote:
>>> Marco, what would the syntax be for adding a file as the log output. Is
>>> it possible to add an already existing file pointer or just the file
>>> name as a string? This would be the ultimate solution as we then can
>>> merge the two log streams from dolfin and logging dependent python
>>> modules such as UFL.
>>>
>>> My boost python skills are really limited so following the inner
>>> workings of this small file is hard for me...
>>>
>>
>> In my old code (where everything is wrapped with boost)
>>
>> after
>>
>> fileout = ostream(cout_buf())
>>
>> fileout will point to std::cout,
>>
>> and after
>>
>> fileout = ostream('new_file_name.txt')
>>
>> fileout will point to a newly opened ofstream.
>>
>> Then, fileout can be passed to any wrapped c++ function that
>> has an std::ostream & argument.
>>
>> I.e., if I have this c++ function
>>
>> void DxOutput(std::ostream & out, const MyFloat t);
>>
>> and I wrap it as
>>
>> BOOST_PYTHON_MEMBER_FUNCTION_OVERLOADS(ofstream_open_overloads,
>> std::ofstream::open, 1, 2);
>> BOOST_PYTHON_MODULE_INIT(_python_util)
>> {
>> ....
>>
>> the wrapping code I've attached
>>
>> ....
>>
>> python::def("DxOutput", DxOutput);
>> }
>>
>> in python I can do
>>
>> t=0.01
>> fileout = ostream('new_file_name.txt')
>> DxOutput(fileout, t)
>>
>> if I want to write with DxOutput into new_file_name.txt,
>>
>> or
>>
>> fileout = ostream(cout_buf())
>> DxOutput(fileout, t)
>>
>> If I want DxOuptut's output on the screen.
>>
>> Note however that I can't write directly from python into fileout
>> (and I fear that this is what you are looking for :( .
>> At least, I've not even tried to do it (perhaps one should start
>> extractig the file descriptor, as explained here:
>>
>> http://www.ginac.de/~kreckel/fileno/
>>
>> )
>>
>> Or
>> http://stackoverflow.com/questions/2378005/c-iostreams-and-python
>>
>>
>> Hope this helps.
>>
>> --
>> You received this bug notification because you are a member of DOLFIN
>> Team, which is subscribed to DOLFIN.
>> https://bugs.launchpad.net/bugs/1072694
>>
>> Title:
>> list_timings() cannot be redirected to a file or a variable in python
>>
>> Status in DOLFIN:
>> Confirmed
>>
>> Bug description:
>> In python it is not possible to redirect the output of list_timings()
>> to a file.
>>
>> set_output_stream(std::ostream& out) in log.ccp is not working in
>> python because of problems in wrapping cpp ostream
>>
>> see also https://answers.launchpad.net/dolfin/+question/211271
>>
>> To manage notifications about this bug go to:
>> https://bugs.launchpad.net/dolfin/+bug/1072694/+subscriptions
>